Mash problems?

[goose]

Another hint to increasing your efficiency during the sparge is to knife the grain bed during the runoff.  I use the handle of a stainless steel spoon and knife the bed in a checkerboard pattern a few inches deep several times during the runoff.  It helped increased my efficiency.  Just remember not to go too deep in the grain bed so you don’t cause channels.  This is mostly used in a fly sparge scenario.

I also totally agree with Martin on the stratifying of the wort in the kettle.  You have to stir it up to get a good reading.  I have had this happen to me in the past.  You can verify this by taking a measurement at the output valve of the kettle and again at the top of the kettle without stirring.  They will vary a lot.
I also take a second measurement right when the wort starts to boil as a double check since the things really start to move around from the convection in the kettle and the wort becomes a bit more homogeneous.

Finally, I agree with taking a post mash gravity (i.e. first runnings) to see where you are efficiency wise.  It should be about 50% or so higher than your predicted OG.  Since I am anal retentive, I also take measurements in the kettle during the runoff (after stirring) to see how far the kettle gravity has dropped from the first runnings.  that way I can dial in my kettle gravity with either water or DME, if needed.

[denny]

@klickitat_jim

@denny

I did some quick crunching.  It looks like you were only expecting about 51% yield, which is extremely low in itself.  A very conservative 70% yield – easily achieved with a conventional (I hate the term “fly”) sparge and your ratios – should get you an OG north of 1.067.  I would guess there are two issues.  First, at your water-to-grist ratio of 2.6:1 (1.23 qt/lb) it may have been difficult to adequately stir a 10 gal, 20 lb batch.  (5 gal, no problem.)  Could have left dry spots, even. Then there’s the speed of your sparge.  I’d say you should try a thinner mash – at least 3:1 or 1.45 qt/lb – and slow down the sparge.  The proper rate for sparging is really dependant on the depth of the grain bed, not the total weight or volume.  If your depth is on the order of a foot, recirculation and runoff should take probably an hour or so.  Really, let the rate set itself:  find where it flows smoothly and crystal clear by gravity without pulling solids through the filter bed.  Thoroughly mixing the mash,  periodically stirring it to help sugar migrate into solution, and letting the sparge percolate through more slowly should get much more extract out.

(Fixed typo)

Dude, you’ve brought out my inner pedant…why is fly sparging “conventional” and batch sparging is not?  Batch sparging was around for a long time before fly sparging.  I’d argue that it’s more “conventional”.  Actually, I’d argue to not even use the word “conventional”…cal them by what they are.  If you don’t like “fly”, how about “continuous”?

I vote for “decreasing rate of return sparge” instead of Fly Sparge, simply “Sparge” instead of Batch Sparge, and instead of No Sparge you just dont mention sparging at all.

Always the pragmatist!